Bulgaria opens national radioactive waste repository

Bulgaria has officially opened the National Repository for low- and intermediate-level radioactive waste at the Radiana site near the Kozloduy Nuclear Power Plant. The opening ceremony took place on 14 April 2026 with the participation of Bulgaria’s acting Minister of Energy, Traycho Traykov. The Bulgarian side presents this facility as a key element in completing the national radioactive waste management system.

The construction of the repository was financed primarily through the Kozloduy International Decommissioning Support Fund, managed by the EBRD. According to reports released at the opening, the construction cost amounted to approximately EUR 76 million from the fund, while an additional EUR 34 million was provided by Bulgaria as national co-financing.

The repository is located in the immediate vicinity of the Kozloduy NPP and is intended for processed and conditioned low- and intermediate-level waste generated in Bulgaria. This includes waste from the energy, medical, industrial, and other sectors, as well as materials generated during the decommissioning of the first four power units of the Kozloduy NPP. At the same time, the repository is not intended for high-level radioactive waste or spent nuclear fuel.

The design capacity of the facility is 66 reinforced concrete cells capable of holding around 19,000 containers. During the first stage, 22 cells were constructed with a capacity of 6,336 containers; this phase is intended primarily for waste from the decommissioning of Units 1–4 of the Kozloduy NPP. The Bulgarian side states that the repository will be filled over approximately 60 years, after which it will remain under supervision for more than 300 years.

According to official and sectoral sources, the facility is a near-surface trench-type repository with a multi-barrier protection system. At the end of March 2026, the state acceptance commission confirmed the facility’s compliance with construction and regulatory requirements, opening the way for its commissioning.

IDR commentary

The opening of such a facility is important not only for Bulgaria, but for the entire Danube region. The Radiana site is located near the Danube and not far from the Romanian bank, which makes long-term safety, groundwater monitoring, seismic control, and transboundary environmental trust critically important issues. The environmental impact assessment materials for the project directly describe pre-operational hydrogeological, radiological, and seismic monitoring programmes, which indicates the high sensitivity of the location and the need for continuous oversight.

Analyzing the significance of this development for Ukraine, IDR experts emphasize the following.

First, this is an example of how Danube basin countries are moving from temporary solutions toward a long-term institutional infrastructure for radioactive waste management. For Ukraine, which will face a growing agenda in nuclear safety, future decommissioning of certain facilities, and integration with European standards, the Bulgarian case is important from the perspective of regulatory design, international financing, and technical supervision. This is an analytical conclusion based on the nature of the Bulgarian project itself and the role of the EBRD and European support mechanisms.

Second, for the Ukrainian Danube region, the issue has a direct transboundary dimension. Although the facility is located not near the Ukrainian border, but in the Bulgarian-Romanian sector of the Danube, any new nuclear or radiation-sensitive infrastructure within the river basin increases the importance of international data exchange, basin-wide environmental monitoring, and coordinated response in the event of incidents. For Odesa region and Ukrainian Danube communities, this means the need to consistently advocate for high standards of transboundary information sharing and environmental transparency throughout the Danube.

According to the Director of the Institute, Vitalii Barvinenko, the opening of the repository demonstrates that nuclear energy and waste management remain part of the region’s long-term energy resilience.

“Bulgaria is simultaneously developing decommissioning infrastructure for old units while maintaining the operation of active nuclear capacities at Kozloduy. For Ukraine, this brings into focus not only the issue of electricity generation, but also the full fuel-and-waste cycle, without which no nuclear strategy can be considered complete,” V. Barvinenko noted.

In conclusion, the opening of Bulgaria’s national radioactive waste repository is a highly important event for the Danube region. It underlines that modern nuclear policy in Europe includes not only electricity generation, but also the creation of long-term, financially secured, and internationally supervised solutions for the safe management of radioactive waste. For Ukraine and the Ukrainian Danube region, this is прежде всего a signal of the importance of combining energy policy, environmental security, and transboundary risk management.